Operant training techniques are used to establish behavioral measures for noxious and non-noxious thermal stimuli presented to the upper lip of the rhesus monkey. The primary paradigm for studying supra-threshold warming stimuli has been a reaction time measure. Currently, the project has been expanded to describe the behavioral effects of both intensity and rate of stimulation by using the fastest reaction time method. Additionally, monkeys are being shaped to respond to the termination of a non-noxious warming stimulus so that subsequent escape behavior elicited by noxious stimuli can be used to infer "pain". In awake responding animals, behavioral and neural events are correlated to determine the role of various trigeminal brain stem neurons in pain and temperature transmission. BIBLIOGRAPHIC REFERENCES: Dubner, R. and Beitel, R.: A behavioral animal model for the study of pain. In Weisenberg, M. and Tursky, B. (Eds.): Pain: Perspectives in Therapy and Research, Plenum Press, New York, 1976, pp. 155-170. Dubner, R. and Beitel, R.E.: Peripheral neural correlates of escape behavior in rhesus monkey to noxious heat applied to the face. In Bonica, J.J. and Albe-Fessard, D. (Eds): Advances in Pain Research and Therapy, Raven Press, New York, 1976, pp. 155-160.